High current cable engagement tool

ABSTRACT

A tool for aiding in either engaging or disengaging large, heavy, electrical power plugs and receptacles having lug shaped ears. A special scissor shaped tool temporarily fits in rotatable engagement with the ears, and a screw mechanism on the tool rotates to force engagement or disengagement as desired. while the tool maintains azimuthal alignment of the plug and receptacle.

Unite States Patent Stone HIGH CURRENT CABLE ENGAGEMENT TOOL Inventor: Kenneth F. Stone, Berkeley, Calif.

Assignee: The United States of America as represented by the United States Atomic Energy Commission, Washington, D.C.

Filed: May 31, 1972 Appl. No.: 258,399

US. Cl. 29/203 P Int. Cl. B23p 19/00, H05k 13/00 Field of Search 29/203 P, 200 P,

References Cited UNITED STATES PATENTS Frank et a1. 29/203 P Dec. 11, 1973 3,257,711 6/1966 Van Rijsewijk 29/203 P Primary ExaminerThomas H. Eager Attorney-John A. Horan [57] ABSTRACT A tool for aiding in either engaging or disengaging large, heavy, electrical power plugs and receptacles having lug shaped ears. A'special scissor shaped tool temporarily fits in rotatable engagement with the ears, and a screw mechanism on the tool rotates to force engagement or disengagement as desired, while the tool maintains azimuthal alignment of the plug and receptacle.

6 Claims, 1 Drawing Figure HIGH CURRENT CABLE ENGAGEMENT TOOL BACKGROUND OF THE INVENTION This inventionwas made in the course of, or under contract W-7405-eng-48 with the United States Atomic Energy Commission.

In the field of high-power applications for conducting large electrical currents, hand operated or solid connections are used. Thus, it would be a technical advance to provide a tool for making or breaking these connections. Also, in areas of high radiation levels, such as in accelerator beam caves, where quick highpower electrical connections and/or disconnections are advantageous for large magnets for transporting charged particle beams, it would be a technical advance to provide a quick acting tool for such connections, and/or disconnections to reduce the radiation exposure to personnel who have to make or break the connection at periodic intervals, e.g. to move the magnets, or to replace the magnets for different experiments.

It is an object of this invention therefore, to provide a tool for aiding in either engaging or disengaging a large heavy electrical power plug andreceptacle;

It is also an object of this invention to provide means for connecting and/or disconnecting large magnets in accelerator beam caves;

It is another object to minimize the radiation hazard to personnel in operating large magnets for transporting'charged particle beams;

It is a still further object toprovide a screw mechanism on a tool for forcing the engagement or disengagement of heavy electrical powered plugs and receptacles.

SUMMARY OF THE INVENTION This invention provides a tool for aiding in either engaging or disengaging a large, heavy electrical power plug and receptacle for conducting large electrical cur rents. More particularly, this invention provides a remotely operated device for gripping a heavy electrical power plug and biasing vit intoor out of a receptacle therefor. In one embodiment, a scissors-shaped tool is provided having ends that are temporarily fitted -in-roa features will be particularly pointed out in the apparent claims.

BRIEF DESCRIPTION OF THE DRAWINGS The drawing is a partial side view of the remotely operated apparatus of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT This invention is useful for aiding in either engaging or disengaging alarge, heavy electrical power plug and receptacle. As such, this invention is particularly useful for engaging or disengaging high-current cables and re-v ceptacles for large magnets in an accelerator beam' cave for transporting charged particle beams. However, since such cables and their associated. plugs and receptacles are quite heavy and cumbersome, and/or involve the necessity for large pluggin -in and pulling out forces, e.g. when silver-soldering o welding occurs at such joints, this invention'can be used in any application requiring the engagement and/or disengagement of such electrical plugs and receptacles. Thus, this invention has the advantage of reducing the effort and man power required for such applications, as well as reducing the safety hazards therefrom.

Referring to the FIGURE the device 10, comprises scissors means 11, which are actuated by a threaded drive means 12 connected between the scissors arms to adjust the angle between the scissors arms. To this end, a conventional crank (not shown for ease of explanation) inserts into a slot 13 in the end of the drive means for turning the thread 12' of the drive means. One suitable crank, for example, comprises a standard k" drive speed or a racket-wrench that engages slot 13 to either engage or disengage plug 71 and receptacle as described in more detail hereinafter.

Advantageously, as shown in the figure, a first pair 17 of parallel scissors arms 19 have a rectangular crosssection cross-bar 20 formed with pins 21 therein that hold arms 19 in parallel relationship while they rotate together at joint 22 around an axis 23 formed by hex headed clamp screws 24, which thread into the opposite ends of sleeve 25 for contacting the latter against the inside of other parallel arms 26 of scissors means 11 at joint 22. Suitable washers 31 between the inside 33 of the head 35 of screws 24 and the outside of arms 19 provide relative rotatable movement between screws 24, arms 19, and arms 26 at joint 22.

Thread 12' actuates the scissors mechanism 11 to open and close by biasing the arms together or apart to adjust the angle 0 there between. To this end, one end of drive means 12 pushes cross-bar 20 at a collar 39 that forms a suitable race and thrust bearing assembly in a groove 40 on one side of cross-bar 20 around the outside of rod 41. Likewise this same end of drive means 12 pulls cross-bar 20 at another like collar 42 having a suitable race and thrust bearing, which may be held by a set screw on rod 41. In this regard, the two collars 39 and 42 of cross-bar 20 hold the cross-bar 20 and arms 19 together as a unit with rod 41 as it rotates in the collars so that thread 12' on rod 41 pushes and pulls against cross-bar 43, which holds arms 26 in parallel as the rod 41 rotates in either a clockwise or a counter-clockwise direction therein and moves transversely therethrough to move the cross-bar 43 toward or away from cross-bar 20.

As will be understood from the above, arms 26 form a second pair 51 of scissors arms that are heldtogether in parallel with its cross-bar 43. In this regard, the

thread 12"on rod 41 spins in a thread 57 in a hole 59 in cross-bar 43, while pins 61 hold cross-bar 43 with the two arms 26 in parallel in pair 51 as they also pivot around axis 23 in joint 22. Thus, the turning of thread 12' by means of a crank in slot 13, causes the arms 26 to pivot in parallel in pair 51 around axis 23 to adjust the angle 0 between the second parallel scissors arms 26 and the first parallel scissorsarms 19, which crossbar 21 holds together in parallel in pair 17. Cross-bar 43 also forms spaced-apart holes adjacent to and normal to pins 61 for easy removal of the pins 61 from cross-bar 43.

Should shaped free-ends 69 of arms 19 and 26 of the described scissors means 1 1 respectively connect in rotatable, selectively engageable contact with a high current plug 71 and a high current receptacle 75 for plug 71 in accordance with this invention, as described in more detail hereinafter, the selective clockwise or counter clockwise rotation of thread 12' on rod 41 will selectively engage and/or disengage the plug and receptacle by varying the angle between the arms 19 and 26. In this regard, the mechanical advantage and low friction provided by the described scissors means 11 and thrust bearing collars, is ideally adapted for remotely aligning and connecting large current plugs and receptacles where large engagement and/or disengagement forces are required. In this regard, heavy high current plugs and receptacles can cause arcing and welding of the plugs and receptacles. Thus, the device 11 of this invention effects the simple, safe, efficient, speedy and remotely operated trouble-free disconnection of such plugs without the need for the combined efforts of many persons, crowbars, hammers, etc. In this manner, the means 11 of this invention is likewise helpful in reducing the radiation hazard to personnel who have to connect and/or disconnect plugs and receptacles in beam caves or other areas subject to penetrating radiation.

Oppositely slanted keyways 77 for locks 79, in accordance with this invention, provide the abovementioned connection of the free ends 69 of arms 19 and 26 with plug 71 and receptacle 75 for selectvely engaging and disengaging the same. As will be understood in more detail hereinafter, this involves an oppositely slanted arrangement 80 at the ends of the described arms 19 and 26 that permits the application of a selective force of engagement or disengagement through the full travel of the threaded drive means 12. Moreover, this oppositely slanted arrangement 80 applies pressure in both directions in a way that prevents the arms 19 and 26 from slipping off lugs 81 forming the locks 79 on the plug and receptacle for pulling and- /or then plugging them in, as described in more detail hereinafter. In this regard, for. ease of explanation the plug is shown at the right of the figure and the receptacle is shown at the left thereof, although, as understood in the art, their positions may be reversed by one skilled in the art based on the description herein.

In regard to the above, the plug 71 and receptacle 75 have special plate assembly means 82 forming the lugs 81 and these fit into the shaped free-ends 69 of arms 19 and 26. To this end, the plate assembly means 82 for receptacle 75 has two straps 85 that connect together at the bottom thereof by means of a screw 86 that connects co-axial interlocking fittings 87 along the axis of screw 86. The straps 85 bend around the outside of the receptacle and hold it under tension by tightening bolt 89 and nut 91 through the ends 93 of straps 85 so that the receptacle lugs 81 line-up with the shaped ends 69 of arms 26. Similarly, another like plate assembly means 82 holds the plug 71 so that its lugs 81 fit into the shaped ends 69 of arms 19. Thus, the threaded drive means 12 aligns and biases the plug 71 into or out of receptacle 75 by holding the latter in its assembly means 82 in contact with the free-ends 69 of arms 26 while increasing or decreasing the angle 0 between the scissors arms 26 and 19, the latter holding the plug 71 with the other assembly means 82 connected to arms 19 by means of its lugs 81.

As understood from the above, the scissors arms form opposing parallel arm members, whereby the shape and position of the ends 69 of arms 19 and 26 and lugs 81 have a critical bearing on the operation of the described device 10. To this end, the shape of the cut-out portions 101 of ends 69 of arms 19 and 26'form the opposing fingers 103 that grip the outside 105 of lugs 81 to keep the lugs 81 from dropping out of the arms 19 and 26. Advantageously, this function is provided by cutting the cut-out portions 101 to form openings 107 having an axis 109 at an angle of 25 1- 2 to the axis 111 of the arms 19 and 26. Also, the fingers 103 of the arms 19 and 26 oppose each other, so that they have long fingers 113, as well as short fingers 115. Also, the two sets of arms are biased apart and come together so that the axis 109 of their respective openings 107 would form an acute angle of 50 with their co-axial arm axes 111 if they were brought to an overlapping position.

In the operation of one sequence for pulling the plug 71 from receptacle 75, the respective plate assemblies 82 tighten around the plug and receptacle so that the lugs 81 thereof have a position for insertion in arms 19 and 26 with a small angle 0 between the arms. Then, the opening 107 of arms 19 and 26 are pushed over the respective lugs 81 of the two respective plate assemblies 82 so that the enlarged head portions 117 of the lugs 81 cannot slip through the openings 107 vertically or horizontally from one side to the other of device 10. Turning threaded drive means 12 in the appropriate direction causes thread 12' selectively to bias the parallel first arms 19 toward and away from the parallel second arms 26 to change the angle 0 thereby to pull or connect the plug 71 and the receptacle 75. Thus, for example, after the plug and receptacle are pulled apart, they are connected by appropriately rotating the threaded drive means 12 to decrease the angle 0, thereby remotely to align and connect the plug 71 and receptacle to complete a cycle. Thus, in other examples, it will be'understood that the cycles can begin either with the pulling or connecting of the plug 71 and receptacle.

In an actual operating device that was tested on June 15, 1971, the described device was able to pull and/or engage a cable weighing 20-25 pounds per foot and containing four copper cables with a force of up to 500 pounds or more, which is sometimes necessary due to welding of the plug and receptacle.

This invention has the advantage of providing a simple, effective and trouble-free tool for safely remotely, selectively, and quickly connecting and disconnecting a power plug and receptacle for conducting electrical power. This tool is especially useful for large, high current cables, and is particularly advantageous for connecting and disconnecting heavy electrical power cables and plugs that are subject to welding. Additionally, this invention is useful in an embient area that is subject to radiation, such as penetrating radiation due to collision with charged particles. To this end, the device of this invention provides a low friction mechanical advantage and a remotely operated scissors tool having a threaded drive means and special connectors for the tool, plug and receptacle.

What is claimed is:

l. A tool for selectively connecting and disconnecting a. plug and a receptacle for large, electrical current applications, comprising a remotely operated scissors means having longitudinally extending scissors arms and low friction threaded drive means formed with thrust bearings for rotating said arms relatively to open and close said scissors arms, and means on said arms for selectively gripping and holding said plug and receptacle for engaging and disengaging the same without dropping the same in response to said opening and closing of said scissors arms in accordance with the operation of said drive means to open and close said scissors arms.

2. The tool of claim 1 in which said scissors means has a first pair of parallel arms and a second pair of parallel arms in opposition thereto, and said first pair of parallel arms grip opposite sides of said plug and said second pair of parallel arms grip opposite sides of said receptacle for biasing the same toward and away from each other in the proper alignment.

3. The tool of claim 2 in which said first and second arms form opposing fingers around openings at an acute angle to the axis of the arms for gripping lugs, and said plug and receptacle have lugs that selectively fit into said openings at said acute angle to prevent the same from dropping out therefrom.

4. The invention of claim 1 in which said scissors arms form opposing members having opposing long and short fingers forming opposing openings there between at an acute angle to each other, and said plug and receptacle form lugs that are selectively inserted into said opposing openings at said acute angle for biasing said plug and receptacle in opposition to each other while said fingers keep said lugs from falling out of said openings.

5. The invention of claim 1 in which said means on said arms form first fingers on first arms forming an opening having an axis in a first direction and second fingers on second arms forming an opening having an axis in a first direction and second fingers on second arms forming an opening having an axis in a second direction at an acute angle to said first direction.

6. The invention of claim 5 in which the angle between said first and second directions and the respective axes of said arms is 25 i 2. 

1. A tool for selectively connecting and disconnecting a plug and a receptacle for large, electrical current applications, comprising a remotely operated scissors means having longitudinally extending scissors arms and low friction threaded drive means formed with thrust bearings for rotating said arms relatively to open and close said scissors arms, and means on said arms for selectively gripping and holding said plug and receptacle for engaging and disengaging the same without dropping the same in response to said opening and closing of said scissors arms in accordance with the operation of said drive means to open and close said scissors arms.
 2. The tool of claim 1 in which said scissors means has a first pair of parallel arms and a second pair of parallel arms in opposition thereto, and said first pair of parallel arms grip opposite sides of said plug and said second pair of parallel arms grip opposite sides of said receptacle for biasing the same toward and away from each other in the proper alignment.
 3. The tool of claim 2 in which said first and second arms form opposing fingers around openings at an acute angle to the axis of the arms for gripping lugs, and said plug and receptacle have lugs that selectively fit into said openings at said acute angle to prevent the same from dropping out therefrom.
 4. The invention of claim 1 in which said scissors arms form opposing members having opposing long and short fingers forming opposing openings there between at an acute angle to each other, and said plug anD receptacle form lugs that are selectively inserted into said opposing openings at said acute angle for biasing said plug and receptacle in opposition to each other while said fingers keep said lugs from falling out of said openings.
 5. The invention of claim 1 in which said means on said arms form first fingers on first arms forming an opening having an axis in a first direction and second fingers on second arms forming an opening having an axis in a first direction and second fingers on second arms forming an opening having an axis in a second direction at an acute angle to said first direction.
 6. The invention of claim 5 in which the angle between said first and second directions and the respective axes of said arms is 25* + or - 2*. 